Structure for fixing printed circuit board and method of fixing thereof

ABSTRACT

A structure of fixing a printed circuit board includes a mold frame coupled with a display panel, a printed circuit board positioned at a rear surface of the display panel and electrically connected to a pad portion of the display panel, and an insulating film covering an outer surface of the printed circuit board.

The present invention claims the benefit of Korean Patent ApplicationNo. 30762/2004 filed in Korea on Apr. 30, 2004, which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display device, andmore particularly, to a structure of fixing a printed circuit board on aliquid crystal display panel and a method for fixing thereof thatprovide an insulating film to protect the printed circuit board and fixthe printed circuit board without a hook or a screw.

2. Discussion of the Related Art

A display device is considered to be more and more important as visualinformation transmission increases. In addition, as display devicesbeing increasing used in portable devices, they need to have highresolution images, lightness, thin profile, compact size, and low powerconsumption.

In general, display devices are classified into a light-emitting type ora non-light-emitting type. The light-emitting type display devicesinclude cathode ray tube (CRT) devices, electro-luminescent (EL)devices, light emitting diode (LED) devices, vacuum fluorescent display(VFD) devices, field emission display (FED) devices, and plasma displaypanel (PDP) devices, which emit light by themselves. The non-lightemitting type display devices include liquid crystal display (LCD)devices, which cannot emit light by itself.

LCD devices use the optical anisotropy and polarization properties ofliquid crystal molecules to generate a desired image. In particular,liquid crystal molecules can be aligned in a specific orientation, whichcan be controlled by applying an electric field across the liquidcrystal molecules. Due to optical anisotropy, incident light isrefracted according to the orientation of the liquid crystal molecules,thereby generating the desired image.

FIG. 1 is a disassembled perspective view schematically showing a liquidcrystal display device according to the related art. In FIG. 1, a liquidcrystal display device includes a liquid crystal display panel 10,driving circuit units 20 and 30, and a backlight unit 40, which areenclosed by an upper case 50 and a lower case 60. Although not shown,the liquid crystal display panel 10 includes an array substrate, a colorfilter substrate, and a liquid crystal layer formed between the arraysubstrate and the color filter substrate.

In addition, the driving circuit units 20 and 30 supply driving signalsto the liquid crystal display panel 10 for displaying an image on theliquid crystal display panel 10. The driving circuit units 20 and 30include printed circuit boards 21 and 31 to which tape carrier packages(TCP) 22 and 32 are attached, respectively. The tape carrier package 22is a gate tape carrier package, and the tape carrier package 32 is adata tape carrier package. Although not shown, the driving circuit units20 and 30 also include other devices, such as a timing controller, adata driver integrated circuit (IC) mounted on the data tape carrierpackage 32, and a gate driver integrated circuit mounted on the gatetape carrier package 22.

The backlight unit 40 is at a rear side of the liquid crystal displaypanel 10 and emits light onto the liquid crystal display panel 10. Inaddition, the backlight unit 40 includes a lamp assembly including afluorescent lamp (not shown) for generating light, a reflection sheet 41for reflecting light emitted from the fluorescent lamp, a light guideplate 42 for guiding the reflected light, and a plurality of opticalsheets 43 for diffusing and collecting light transferred from the lightguide plate 42. Further, the backlight unit 40 is mounted in a moldframe 44.

Further, the data tape carrier package 32 is bent to position the dataprinted circuit board 31 at a rear surface of the liquid crystal displaypanel 10. In addition, the gate tape carrier package 22 is bent once.Since the gate printed circuit board 21 generally is small, the gateprinted circuit board 21 is positioned along a side surface of the moldframe 44 by bending the gate tape carrier package 22 once. Bypositioning the gate printed circuit board 21 along the side surface ofthe mold frame and positioning the data printed circuit board 31 at therear surface of the liquid crystal panel 10, a display area of theliquid crystal display panel 10 is increased.

FIG. 2A is a planar view of a portion of a rear side of a liquid crystaldisplay device without a lower case according to the related art. InFIG. 2A, the data printed circuit board 31 is attached and affixed tothe mold frame 44 by a hook H. By forming the hook H at a predeterminedportion of the mold frame 44 and inserting the data printed circuitboard 31 into a lower portion of the hook H, the data printed circuitboard 31 is affixed on the mold frame 44. However, in a process ofassembling and disassembling the printed circuit board 31, the tapecarrier package 32 or a chip-on-film (COF) attached to the printedcircuit board 31 can be damaged easily. Thus, it typically takes longertime to assemble or disassemble a printed circuit board, which isaffixed by a hook. In addition, whenever the hook needs to be removed,the printed circuit board also can be damaged by the process.

FIG. 2B is a planar view of a portion of a rear side of another liquidcrystal display device according to the related art. In FIG. 2B, thedata printed circuit board 31 is attached and affixed to the mold frame44 by screws S. By fastening the screws S through the data printedcircuit board 31 at predetermined portions of the mold frame 44, thedata printed circuit board 31 is affixed on the mold frame 44. However,it typically takes longer time to ensure the screws S are securelyfastened, thereby increasing an operator's work load and reducingproductivity.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a structure of fixinga printed circuit board and a method for fixing thereof thatsubstantially obviate one or more of the problems due to limitations anddisadvantages of the related art.

An object of the present invention is to provide a structure of fixing aprinted circuit board and a method for fixing thereof using aninsulating film, such as polyethylene terephthalate (hereinafter called“PET”), for affixing and protecting the printed circuit board without ahook or a screw.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, thestructure of fixing a printed circuit board includes a mold framecoupled with a display panel, a printed circuit board positioned at arear surface of the display panel and electrically connected to a padportion of the display panel, and an insulating film covering an outersurface of the printed circuit board.

In yet another aspect, the structure of fixing a printed circuit boardincludes a mold frame coupled with a display panel, a printed circuitboard positioned at a rear surface of the display panel and electricallyconnected to a pad portion of the display panel, a first insulating filmattached to the mold frame and the printed circuit board, the firstinsulating film covering an outer surface of the printed circuit boardand having a protruding portion, and a second insulating film attachedto the mold frame and the first insulating film, the second insulatingfilm covering the protruding portion.

In another aspect, the method for fixing a printed circuit board on adisplay panel includes coupling a mold frame with the display panel, thedisplay panel having a printed circuit board positioned at a rearsurface of the display panel and electrically connected to a pad portionof the display panel, attaching a first insulating film to the moldframe and the printed circuit board, the first insulating film coveringan outer surface of the printed circuit board and having a protrudingportion, and attaching a second insulating film to the mold frame andthe first insulating film, the second insulating film covering theprotruding portion.

In yet another aspect, the method for fixing a printed circuit board ona display panel includes coupling the display panel with a mold frame,the display panel having the printed circuit board electricallyconnected thereto, positioning the printed circuit board on a rearsurface of the display panel, and attaching a first insulating film to afirst portion of the mold frame, the first insulating film covering anouter surface of the printed circuit board.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a disassembled perspective view schematically showing a liquidcrystal display device according to the related art;

FIG. 2A is a planar view of a portion of a rear side of a liquid crystaldisplay device without a lower case according to the related art;

FIG. 2B is a planar view of a portion of a rear side of another liquidcrystal display device according to the related art;

FIG. 3 is an exemplary view schematically showing a structure of fixinga printed circuit board according to an embodiment of the presentinvention; and

FIGS. 4A and 4B are exemplary views schematically showing a structure offixing a printed circuit board according to another embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

FIG. 3 is an exemplary view schematically showing a structure of fixinga printed circuit board according to an embodiment of the presentinvention. In FIG. 3, a printed circuit board 131 may have a tapecarrier package (not shown) attached thereon and may be a data printedcircuit board. In particular, the tape carrier package may be bent suchthat the printed circuit board 131 is positioned at a rear surface of aliquid crystal display panel (not shown). An insulating film 170 may becoupled to the printed circuit board 131 and may cover the entire outersurface of the printed circuit board 131, thereby fixing and protectingthe printed circuit board 131. An insulating film 170 may includepolyethylene terephthalate (PET).

In addition, the PET 170 may be coupled to the printed circuit board 131to form an integral body using a double-sided tape (not shown) along anedge region of the printed circuit board 131. This edge region may bealong a short side of a mold frame 144. As a result, the PET 170 mayaffix and protect the printed circuit board 131. In addition, theprinted circuit board 131 may be easily affixed by fixing the PET 170 tothe printed circuit board 131 using the double-sided tape without afixing means, such as a hook and a screw.

FIGS. 4A and 4B are exemplary views schematically showing a structure offixing a printed circuit board according to another embodiment of thepresent invention. As shown in FIGS. 4A and 4B, a first PET 270A mayinclude a protruding portion P protruding toward a mold frame 244 and aprinted circuit board 231 may have a tape carrier package (not shown)attached thereon. The printed circuit board 231 may be a data printedcircuit board. The first PET 270A may cover the entire outer surface ofthe printed circuit board 231 and may be coupled to the printed circuitboard 231 to form an integral body using a first double-sided tape 280Aalong an edge region of the printed circuit board 231. The first PET270A also may be cover an upper surface of the mold frame 244 adjacentto a gate pad portion of a LCD display panel.

In addition, a second PET 270B may cover a portion of the mold frame 244(hereinafter called a “mold frame of a long side”) which overlaps theprotruding portion P. The second PET 270B also may cover the protrudingportion P. In particular, the second PET 270B may be coupled to theprotruding portion P and the mold frame 244 using a second double-sidedtape 280B. The first PET 270A may be a source PET, and the second PET270B may be a gate PET.

Thus, the printed circuit board 231 may form an integral body with thefirst PET 270A, and may be fixed and protected by the first PET 270A.Further, in order to prevent the printed circuit board from moving, thefirst PET 270A may include the protruding portion P overlapping aportion of the mold frame 244 and the second PET 270B may cover theprotruding portion P. Accordingly, the printed circuit board 231 issecurely affixed and protected without much difficulty.

Moreover, a method for fixing a printed circuit board may includemounting the first PET 270A on the mold frame 244, overlapping theprotruding portion P of the first PET 270A with a side portion of themold frame, and mounting the second PET 270B on the mold frame 244covering the protruding portion P. In particular, the first PET 270A andthe printed circuit board 231 may form an integral body using the firstdouble-sided tape 280A. In addition, the first PET 270A may be mountedalong a long side of the mold frame 244.

Further, aligning the second PET 270B to cover the protruding portion Pof the first PET 270A and an upper corner portion of the mold frame 244may be performed before attaching the second PET 270B to the mountingframe 244 using the second double-sided tape 280B. As a result, as shownin drawings, the first PET 270A is securely fixed and the printedcircuit board 231 is prevented from moving. Accordingly, a hook, whichmay cause damages to a tape carrier package or a chip-on-film, is notused. However, if reinforcement is desired, a hook or a screw may beused to additionally fix the printed circuit board.

In addition, productivity increases without increasing fabrication costbecause assembling and disassembling a printed circuit board may becarried easily in comparison to the fixing methods using a hook or ascrew and because an insulating film is not expensive.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the structure of fixing aprinted circuit board and the method for fixing thereof of the presentinvention without departing from the spirit or scope of the invention.Thus, it is intended that the present invention covers the modificationsand variations of this invention provided they come within the scope ofthe appended claims and their equivalents.

1. A structure of fixing a printed circuit board, comprising: a moldframe coupled with a display panel; a printed circuit board positionedat a rear surface of the display panel and electrically connected to apad portion of the display panel; and an insulating film coupled to theprinted circuit board and covering an outer surface of the printedcircuit board so that the printed circuit board is fixed to the moldframe.
 2. The structure according to claim 1, wherein the insulatingfilm is attached to the mold frame using an adhesive.
 3. The structureaccording to claim 1, wherein the insulating film is attached to theprinted circuit board using an adhesive.
 4. The structure according toclaim 3, wherein the adhesive includes a double-sided tape.
 5. Thestructure according to claim 1, wherein the insulating film completelycovers the outer surface of the printed circuit board.
 6. The structureaccording to claim 1, wherein the insulating film includes polyethyleneterephthalate (PET).
 7. The structure according to claim 1, wherein themold frame having a hook for affixing a portion of the printed circuitboard.
 8. The structure according to claim 1, wherein the mold framehaving a screw hole for affixing a portion of the printed circuit boardvia a screw.
 9. A structure of fixing a printed circuit board,comprising: a mold frame coupled with a display panel; a printed circuitboard positioned at a rear surface of the display panel and electricallyconnected to a pad portion of the display panel; a first insulating filmattached to the mold frame and the printed circuit board, the firstinsulating film covering an outer surface of the printed circuit boardand having a protruding portion; and a second insulating film attachedto the mold frame and the first insulating film, the second insulatingfilm covering the protruding portion, wherein the first and secondinsulating films overlap with each other to fix the printed circuitboard to the mold frame.
 10. The structure according to claim 9, whereinthe first insulating film is attached to the printed circuit board usingan adhesive.
 11. The structure according to claim 10, wherein theadhesive includes a double-sided tape.
 12. The structure according toclaim 9, wherein the second insulating film is attached to the moldframe and the first insulating film using an adhesive.
 13. The structureaccording to claim 12, wherein the adhesive includes a double-sidedtape.
 14. The structure according to claim 9, wherein the firstinsulating film completely covers the outer surface of the printedcircuit board.
 15. The structure according to claim 9, wherein the firstand second insulating films include polyethylene terephthalate (PET).16. The structure according to claim 9, wherein the mold frame having ahook for affixing a portion of the printed circuit board.
 17. Thestructure according to claim 9, wherein the mold frame having a screwhole for affixing a portion of the printed circuit board via a screw.